Motor vehicle transmissions, in particular motor vehicle automatic transmissions, comprise a shift mechanism that includes mutually movable parts such as for example a shift lever operable for selecting gearshift positions corresponding to different transmission gears, a movable spring biased plunger arranged to slide on a contoured surface as the shift lever is moved for selecting a gearshift position for giving the user a gearshift feel, etc.
A known issue associated with the above known shift mechanisms with movable parts relates to free plays due to manufacturing tolerances and wear during use which often results in that the gearshift feel is not as precise as desired.
U.S. Pat. No. 7,661,334 teaches a gearshift mechanism comprising a gearshift lever movable to a gearshift housing that addresses the above issue. A plunger having a conical shape is provided movable to the gearshift lever. A spring urges the plunger with an axial spring force against a contoured surface that is attached to the gearshift housing. An elastically deformable ring is provided between the plunger and the gearshift lever such that, as the plunger passes over the contoured surface, the compression spring is compressed, urging the plunger through the elastically deformable ring such that the conical areas of the slotted ring and those of the plunger slide on one another and the ring expands until it comes into contact with the inner wall of the gearshift lever. This results in centering the plunger relative to the gearshift lever.
There are other known solutions that address free plays between the mutually movable parts. However, they generate another issue that directly impacts user comfort as they generate an annoying noise when the shift lever is operated due to the rigidity of the mutually movable parts in contact.
There is therefore a need for shift selector mechanisms for motor vehicle transmissions capable of at least reducing the above disadvantages while still being effective in use.